The paper deals with a detailed numerical study of the sections of the inverse and ray velocity surfaces for cubic crystals. The figures for the sections of the inverse and ray surfaces by the (001) and (110) planes have been plotted for over 65 crystals and from these, the nature of the cuspidal edges has been discussed. Typical graphs of the inverse and ray surfaces have been given. The parameters characterising the dimensions of the cusps have been tabulated. It is shown that the A-15 compounds exhibit very unusual and interesting wave surfaces at temperatures below superconducting critical temperatures.